Process of impregnating wood.



UNITED STATES PATENT OFFICE.

JULIUS SCHENKEL, OF DORTMUND, GERMANY.

PROCESS OF IMPREGNATING WOOD.

SPECIFICATION forming part of Letters Patent No. 655,459, dated August 7, 1900. Application filed June 9,1899. Serial No. 719,981. (No specimens.)

To all whom, it may concern:

Be it known that I, JULIUS SonEnKnL, chemist,asubject of the Emperor of Germany, residing at Hohenzollernstrasse 9, Dortmund, in the Kingdom of Prussia and Empire of Germany, have invented certain new and useful Improvements in Processes of Impregnating IVood, of which the following is a full, clear, and exact description.

This invention relates to a process for impregnating wood which causes the speciallyprepared antiseptic fluid to permeate the wood more thoroughly and more quickly under even considerably less pressure than is the case by known processes, while much less of the impregnating fluid is required. These results are as follows:

Tar-oil or similar substances which are used for impregnating, either unmixed or mixed with an addition of chloride of zinc, is transformed into a condition of finest division by suspending it in a solution of soap in water. In this manner an emulsion is produced the degree of fluidity of which and the percentage of tar-oil contained therein can be changed as required, according to the proportions used. Therefore the power of the impregnating emulsion to permeate the wood and its consequent effect on the latter can be regulated according to the density and degree of dryness of the wood and purpose for which it is used.

Hitherto the tar-oil used, generally unmixed, has required very great pressure to permeate all pores of the wood, which fact is also the result of the oily and inert character of this substance. The watery solution of the tar-oil effected with soap according to this process is of great mobility and has the capacity to easily adhere to the walls of the cell of which the wood is built up, and thus to cover them with a layer, protecting the same against rot and similar deterioration. Then the wood is impregnated in this manner, the fibers do not retain the impregnating fluid in excess, which is the case when heavy tar-oil is used in the ordinary manner, owing to the peculiar capillary conditions. Therefore a great amount of the impregnating fluid is saved,because the wood takes up only as much of the emulsion as is required to conserve it, the percentage of tar-oil being regulated as required.

Tar-oil solublein water can be prepared in different ways. One suitable way of doing it' consists in the use of one hundred parts of rosin, which is saponified by means of a suit able amount of sodium hydroxide and diluted with water, so that the final result is an aqueous soap solution of about one thousand parts in weight. In this soap solution there are stirred at a moderate temperature about one thousand parts, in weight, of heavy tar-oil, so that the result is a thick but nearly clear solution. If now this solution is poured in a thin stream in one thousand parts,in weight, of warm water, there will be produced a milky emulsion of tar-oil in which the oil is finely distributed to such a degree that the same will not be separated from the water by filtering through filtering-paper. This emulsion is pressed into the sleepers in autoclaves after the wood has been suitably steamed and evacuated.

WVhat I claim, and desire to secure by Letters Patent, is i The process for the preservation of wood which consists in forcing into the Wood under pressure, a preservative substance consisting of a watery emulsion composed of tar-oil, wa ter and soap, the water and soap serving as a means of dissolving and emulsifying the tar-oil, and as a vehicle for conveying and distributing the same through the pores of the wood.

In witness whereof I subscribe my signature in presence of two witnesses.

JULIUS SOHENKEL.

Witnesses:

Loursn BARNES, WILLIAM H. MADDEN. 

